Chapter XIX

RUSSIAN AND AMERICAN LOCOMOTIVE PRACTICE WITH LIQUID

TH

FUEL

The Baldwin Co.'s System.

HE Baldwin Locomotive Co. consider that, while opinions upon atomizers differ as to central jet burners such as the Urquhart, the relative position of the oil supply and other details, their own burner is a satisfactory one, and has been applied

to some 250 locomotives in Russia and the United States. This burner is shown in fig. 37.

It is rectangular in section with two longitudinal passages, the upper one for oil,

the lower one for steam. The oil is regulated by a plug cock on the feed pipes, the handle of which extends to the cab within easy reach of the fireman.

Steam is admitted to the lower port of the burner through a pipe so connected to the boiler as at all times to insure the introduction of dry steam. The valve controlling the steam is placed in the cab close to the fireman's seat. A free outlet is allowed for the oil at the nose of the burner; the steam outlet, however, is contracted at this point by an adjustable plate which partially closes the port, and gives a thin wide aperture for the exit of the steam. This arrangement wire-draws the steam and increases its velocity at the point of contact with the oil, giving a better atomizing effect. A permanent adjustment of the plate can be made for each burner after the requirements of service are ascertained. The moving of the plate is not then required except for cleaning purposes. The oil, as it passes through the burner, is heated to a certain extent by the effect of the steam in the lower portion, and flows freely in a thin layer over the orifice. It is here caught by the jet of steam issuing from the lower port, and is completely broken up and atomized at the point of ignition. The oil is carried into the fire-box in the form of vapour, where it is thoroughly mixed up with air and burns freely.

It is computed that one inch of breadth of slit will serve for 100 square inches of cylinder area, so that the breadth of a burner is B D2x-007854. As only one burner is used, American fire-boxes being narrow, it is apparently the case that one cylinder is intended to be taken, and not the area of both cylinders. D=diameter of cylinder.

Large oil-pipes are used so as to deliver a full supply as far as the regulating cock.

To permit of fine adjustment of the cock its orifice is not circular but square, with the diagonals vertical and horizontal as

shown in fig. 38.

Fig. 38.

OIL REGULATING COCK. BALDWIN LOCOMOTIVE Co.

The necessary changes to fit an engine to use liquid fuel according to the views of the Baldwin Co. are shown in fig. 39. The atomizer is attached below the mud ring, and the spray is directed upwards into the firebox which is fitted with a brick arch, a liner of fire-brick and a base filling the front half of where the grate usually is placed. A small hearth is also placed to catch any drip from the burner, and from the lower corner of the bridge there is built, to protect each side sheet, a triangular wall of bricks extending with its lower point to the back plate. The side walls form the sides of the fire-brick combustion chamber. The ash-pan" is retained with its air dampers to admit air below the fires, and the dampers should shut tight. The inner side of the fire-door is lined with a plate of fire-brick.

In the Vanderbilt box, fig. 40, which is simply a corrugated circular furnace, the arrangement of fire-brick is very similar to the above, but the fuel is sprayed parallel to the fire-box bottom liner. The sprayer is inserted through the closing plate of the furnace mouth, which is also brick protected. The arch and bridge wall are kept well behind the back tube plate, and the space forms a further combustion chamber for the flames.

An ash-pan of modified form is employed as shown. It is recommended not

The

Fig. 40. VANDERBILT FIRE-BOX FOR LIQUID FUEL. BALDWIN LOCOMOTIVE CO.

The weight and volume of oil for a given mileage will be about half that

heat. necessary for coal.

The following information is from the report of the Committee of the American Railway Master Mechanics' Association for 1899

Fuel oil can be used in almost any form of fire-box, the best location for the burner being just below the mud ring, spraying upward into the fire-box. In some recent experiments with oil of 84° gravity, 140°F. flash, and 190°F. fire test, in which the boiler had 27 square feet grate area and 2,135 square feet of heating surface, 8 per cent. being in the fire-box, it was found that there were about 39 pounds of oil burned per square foot of grate area, about 0 45 pounds per square foot of heating surface per hour, the equivalent evaporation from and at 212° being about 12 pounds of water per pound of oil. It was also computed that there should be about one

third of an inch width of burner for each cubic foot of cylinder volume.

Or volumes of both cylinders in cubic feet ÷ 3 = width of burner in inches. This was for ordinary locomotives. For compound engines the amount of steam is 10 per cent. and of fuel 20 per cent, less, and in the foregoing formula only the h.p. cylinder volume ought to be considered. Generally the Baldwin Co. accept oil as worth double its weight of worth of coal, a ratio perhaps a trifle high for English practice and coal.

They give a formula for compound locomotives as follows as a guide to an approximate idea of the value of oil fuel as compared with coal.

Cost of coal per ton (of 2,000 lb.) + cost of handling (say 50 cents) × 10·7 × 7. 2,000 × evaporative power of coal.

= Price per American gallon at which oil will be the equivalent of coal. the price per English gallon multiply by 1.2.

To find

It must be remembered in these computations that the cost of both oil and coal is considered at the place where they are delivered to the engine, and not at the place where they are purchased by the railroad company.

The following gives the weight and volume of crude petroleum based on a specific gravity of 0.91, which is about the average of the Texas oil, as well as that received from South America.

For convenience in obtaining the correct approximate weight of oil, the gravity conversion table No. XXXI may be useful.

In American practice where railroads are so dirty with ash and cinders thrown from the locomotives by the powerful blast employed, the use of oil should give an advantage to any line adopting it that cannot be so securely counted on in Great Britain, where ash throwing is less prevalent.

The use of oil also puts a stop to the choking of the tubes of the boiler and permits, if desired, smaller tubes to be employed, which are now inadmissible on account of liability to choke.

Tubes of one inch diameter might be used if enough could be got in to give the requisite area.

The economy of oil is not merely a question of fuel economy.

Table No. XV gives the economy of oil at its relative value compared with coal on both the the fuel account and all ascertained economies, the second value being based on 1 pound of coal being worth 2 of coal in place of 1, as on the mere fuel account. The extra economies include repairs on locomotives and ash handling. Dr. Dudley's formula for relative price is

2,000 × P WXNXR

=

C; where

P=price of oil per barrel.

W=weight per gallon in pounds.

N=gallons per barrel.

R=ratio of oil to coal = 12 or 2, according to condition taken.

C=price of coal per ton of 2000.

For tons of 2,240 lbs use this number in the numerator in place of 2,000. The weight W multiplied by N will be the same in either American or English gallons, and the barrel is always the same, so that only the pounds per ton need be changed, the price of coal and oil of course being given in the same equivalents, either dollars or shillings.

The Baldwin Co. do not recommend crude oil for use in locomotive work for three reasons, namely, it is more dangerous, it has an exceedingly unpleasant odour, and it is not so economical. As is well known, crude oil contains more or less volatile matter which vaporizes quite readily. With the necessary use of lanterns and open lights round about locomotives, there would be more or less danger of explosions. Furthermore, in the case of a wreck, if the oil tank was ruptured, it would be almost impossible to prevent a fire. As to the odour of the crude oil, it would certainly be extremely unpleasant to ride behind a locomotive fed with Lima crude oil. The reason why crude oil is not so economical as reduced oil is because oil is usually sold by volume, and a gallon of crude oil, instead of weighing 7:3 pounds, weighs from say 6.25 to 6-5 pounds, and, as the heat is directly in proportion to the weight of combustible, a barrel of crude oil will not give so much heat as a barrel of reduced oil. The oil which is now used on the Grazi-Tsaritzin Railway, and is believed to be quite safe to use, is an oil not below 300°F. fire-test. It is fair to add that crude oil can be used on stationary boilers where it is kept in tanks and brought to the boilers in pipes.

In regard to these points the arguments appear sound, in view of the disastrous American experiences of burning railway wrecks, and the one English experience at Abergele; but all crude oils are not so unpleasant as the Lima oil referred to, and the unpleasant odour should not live through the furnace. Still the fire risk of crude oil, with its volatile constituents left in, is a danger to be avoided.

The formule and tables, which result from the comparison of the value of coal and oil in cash go far towards explaining why petroleum has not been used to a much greater extent as a means of heat production. In America at the present time, says Dr. Dudley (1888), it is really more expensive to obtain the same amount of heat from oil than it is from coal.

In experiments on the Pennsylvania Railroad, it was found with oil at 30 cents per barrel, that it cost nearly 50 per cent. more to take the same train of cars 100 miles by means of oil than by means of coal.